FAIRFIELD COUNTY, Conn. -- Startups make up only a small percentage of the U.S. economy, but they are a powerful economic force.

“They are only 8 percent of companies in this country, but they are 20 percent of new jobs,” U.S. Sen. Chris Murphy said at a roundtable discussion held at Comradity in Stamford on Wednesday morning.

Even so, startups face big challenges: Half are gone by year five, Murphy said.

“So we have a phenomenal success rate at the beginning of a startup business’ story in terms of job creation [and] we are more reliant more than ever as state and as a country on their success,” he said.

The reason? Murphy said the large corporations aren’t producing as many new jobs as in the past.

“They are not adding jobs like they were 10, 20, 30 years ago,” he said.

“It is all of you that are adding jobs," Murphy said to those gathered around the conference table, many of whom were entrepreneurs.

Murphy said the government needs to think of ways to help startups succeed and to help get them in the door and over that first bump.

“We’ve got to start thinking bigger than just tweaking a SBA [Small Business Administration] program here or there,” Murphy said.

Stamford Mayor David Martin said the city has a long history of hosting large companies.

“Stamford is known as the place in Connecticut where the big businesses come,” Martin said.

But the majority of the jobs in Stamford are at small businesses, and “that’s where the majority of true creativity, true innovativeness comes from,” Martin said.

It’s a “daunting task” to succeed as a small business, he said. Stamford has a a one-person economic development department, and Martin said the city needs to do more to help entrepreneurs.

Even so, the city has taken steps to help small businesses, including introducing a new website to help entrepreneurial efforts, Martin said.

Several entrepreneurs spoke out at the meeting about their challenges of starting a new company. Many said applying to be certified as a women-owned or minority-owned business is a long and arduous process. Others said it’s difficult to find funding.